From an engineering perspective, how are the 'relieving chambers' above the kings chamber supposed to work?

The 5 layers of horizontal lintels separated by air-gaps are normally described by mainstream archaeologists as 'relieving chambers' to share and spread the load of the thousands of tons of rock above the kings chamber.
The builders obviously understood the principles of a corbelled arch since it was used in both the grand gallery and other pyramids.
They also understood the simple triangular arch, since this was incorporated in the queens chamber, and at the top of the relieving chambers above the kings chamber.

So, back to the original question, how do the relieving chambers work? (or maybe they don't?) The horizontal lintels have empty space above and below, so are presumably unloaded? The width of each chamber is constant, so can't be acting like a corbelled arch. The only elements actually doing any load spreading are the lintels that make up the triangular arch right at the top. So what's the purpose of all the layers of horizontal lintels? They must have taken a lot of additional work for no (engineering) purpose - not that I can see anyhow.
UPDATE - some theories from elsewhere on the net. A triangular arch directs the load to the side and below the bottom of the arch. For the arch to work, it needs to re-direct the load onto a secure and stable area of masonry. The most noticeable result of the 5 layers of 'relieving chambers' was to require the arch to move about 10 meters higher than it needs be.
Maybe the triangular arch was placed where it was to avoid loading the areas immediately to the side of the kings chamber? and maybe this was needed because those areas contained voids or some areas of structural weakness? A lot of 'maybes', I know.
